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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-29 18:55:21 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-02-02 21:37:41 +0400 |
| commit | 97f1040982d7935716e9a45a26ccd5cc8fe92f8c (patch) | |
| tree | 158cd337307a4a4e09a3fb5110f29ab0136bef6c /arch | |
| parent | 3c424f359898aff48c3d5bed608ac706f8a528c3 (diff) | |
| download | linux-97f1040982d7935716e9a45a26ccd5cc8fe92f8c.tar.xz | |
Revert "ARM: 7304/1: ioremap: fix boundary check when reusing static mapping"
This reverts commit 3c424f359898aff48c3d5bed608ac706f8a528c3.
Joachim Eastwood reports:
| "ARM: 7304/1: ioremap: fix boundary check when reusing static mapping"
| Commit: 3c424f359898aff48c3d5bed608ac706f8a528c3 in Linus master
|
| Breaks booting on my custom AT91RM9200 board.
| There isn't any error messages or anything that indicates what goes
| wrong it just stops after; Uncompressing Linux... done, booting the
| kernel.
|
| Reverting it makes my board boot again.
and further debugging reveals:
ioremap: pfn=fffff phys=fffff000 offset=400 size=1000
ioremap: area c3ffdfc0: phys_addr=200000 pfn=200 size=4000
ioremap: found: addr fef74000 => fed73000 => fed73400
Clearly, an area for pfn 0x200, 16K can't ever satisfy a request for pfn
0xfffff. This happens because the changed if statement becomes:
if (0x00200 > 0xfffff ||
0xfffff000 + 0x400 + 0x1000-1 > 0x00200000 + 0x4000-1)
and therefore:
if (0x00200 > 0xfffff ||
0x000003ff > 0x00203fff)
The if condition fails, and so we _believe_ that the SRAM mapping fits
our request. Clearly that's totally bogus.
Moreover, the original premise of the 'fix' patch was wrong:
| The condition checking boundaries of the requested and existing
| mappings didn't take in-page offset into consideration though,
| which lead to obscure and hard to debug problems when requested
| mapping crossed end of the static one.
as the code immediately above this loop does:
size = PAGE_ALIGN(offset + size);
so 'size' already contains the requested offset into the page.
So, revert the broken 'fix'.
Acked-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mm/ioremap.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index ba159370fa5f..80632e8d7538 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -225,8 +225,7 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, if ((area->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype)) continue; if (__phys_to_pfn(area->phys_addr) > pfn || - __pfn_to_phys(pfn) + offset + size-1 > - area->phys_addr + area->size-1) + __pfn_to_phys(pfn) + size-1 > area->phys_addr + area->size-1) continue; /* we can drop the lock here as we know *area is static */ read_unlock(&vmlist_lock); |